Process for the manufacture of cellulose esters of fatty acids.



BRUNO RICHARD SEIFEBT AND FRIEDRICH TODTENHAUPT, OF BADEBEUL, NE DBESDEN, GERMANY, ASSIGNORS T CHEMISCHE FABRIK VON HEYDEN, AKTIEN- GESELLSCHAFT, OF RADEBEUL, NEAR DRESDEN, GERMANY.

7 raocess FOR THE MANUFACTURE or CELLULOSE ssues or marry ACIDS.

. 051,165 Specification of Letters Patent. yatgntcd Jzln 21 1913.

No Drawing. Application filed November 29. 1910. Serial No. 594,858.

unchanged and part of it is liydrolized. It 55 is therefore a remarkable fact, which 'we have found, that the chloi'ids of sulfuric acid act much better than even'the chlorids of phosphoric acid. and give a product of great technical value. W'hen working ac- 60 cording to the directions of the said Patent 10253 of 1903 a dark colored. gelatinous substance is obtained. which, in the further course of manufacture, gives a yellowish brown acetyl cellulose, only partially solu- 65 ble in chloroform. If. on the contrary, instead of phosphoric acid chlorid, 1 part by weight of sulfuryl chlorid is added to the same quantities of cellulose, acetic anhydrid and glacial acetic acid, a short heating up to 70 55 to 60 C. is sufficient to obtain in about half an hour a solution which is as clear as water. a

While sulfuric acid at and above 50 C. destroys the solution of acetyl cellulose in 76 stat-u 'luwcc'ndi by decomposing it and rendering it dark, and while phosphorous oxychlorid and phosphorous pentachlorid at about 55 C. yield dark, gelatinous sub- To all whom it may concern:

Be it known that we, BRUNO Ricim m SmrER'r, chemist, a subject of the King of Saxony, and resident" of Albertstrasse 6,

Radebeul, near Dresden, Kingdom of Saxony, German Empire, an Faniomcir 'lon- TENHAUPT, chemist, a subject of the King of Prussia, and resident of Sedanstrasse'ii, Radebeul, near Dresden, Kingdom of Sax 10 ony, German Empire, have invented a new and useful Improvement in the Process for the Manufacture of Cellulose Esters 0 Fatty Acids, of which the following is a specification. r

The manufacture ofacetic esters of cellulose has hitherto been effected in different ways. The first method was to cause dehydrated salts of acetic acid and acetyl chlorid to act upon cellulose or allied products (liydrocellulose and the like). Another old method consisted in causing acetic acid anhydrid, with or without a diluent to act upon the. different celluloses, sulfuric am being employed as a condensing-agent. In

order to obtain technically useful triaoetyl I p n s n this way r must be k n stances 1n 7 to 8 hours, sulfuryl chlorid, 80

that the temperature does not rise to 50 0- when heated to 50 to 80 C. in the course of or more (German Patent 159524) as at such a short time (s to 2 hours) gives solutions of much lighter color than those obtained by temperature the sulfuric acid will destroy sulfuric acid at-a temperature less than so cellulose as well as the cellulose esters 50 C. Sulfuryl chlorid does not decompose 85 formed.

In the specification of British Patent ll'o. cellulose and acidyl cellulose as violently as v sulfuric acid and phosphoric chlorid do, and

10243 of 190 it is proposed to acetyl ze cellulose by acetic anhydrid and glacial therefore no special precautions are necesacetic acid with addition of a suitable iiin- -y, A th advantage f h pmcess i eral acid chlorid, and as suitable n inei'a that good and technically useful solutions of 9 acid clilorids,thechlorids of phosphoric ac acetyl cellulose canbe obtained by employing only one half and even less of the quanare specified. The invention set forth in the said Patent No. 10243 of.1903 does not tity of acetic anhydrid than when acetylizing with sulphuric acid at ordinary tem- 40 refer generally to the employment of any mineral acid chlorid whatever, but onlyto perature, 95

the chloride of phosphoric acid, as only these Example 1: 10 parts by weight of cellulose in the form of cotton. wood cellulose are said to be suitable for the purpose. The

or any other cellulose products, are heated process already fails if these suitable chlorids of phosphoric acid are substituted by to to 80 C. together with 18 to 9.0 parts the nearest allied chlorid, viz. that of the phosphorous acid, If 1, 7 or even l. 6 parts by weight of phosphorous tr chlorid are added to 10 parts of cellulose in the glacial acet c acid and one part of sulfuryl chlorid, until complete solution is effected. It is also possible to work with sulfuryl chlorid form of cotton fleece, 30 parts of glacial without heating, if its quantity is increase acetic acid and 30 parts of acetic anhydrid The solution takes place in some days (4-8), 105 (the proportions given in the example of the without substantia raising of the tempera- Pateut 10243 of 1903) and heated during 8 ture. The sulfuryl chlorid may be substihoi'irs to 0., most of the cotton remains tuted wholly or in part by other chlorids of of acetic anhydrid, about -10 to parts of ..'sulfuric acid, 6.

lose are soaked with 50 v uents may be added or a dil rosulfonic acid or the like Example 2: 10 parts lose are soaked with by using conany diificulty,

chlorid of sulcentrated formic acid and a no acid. Example 3: 10 parts by weight of cellu- .9- pyrosulfuryl chlorid, chlo parts 01: more of vantageous not cotton) ordinary air dried state,

free it from all moisture by drying it perfectly, byartificial means, for instance at a temperature of about 105 C.

at we claim is:

1. The process ters of fatty acids, cellulose with fatty fied.

2. The process of producingcellulose esters of fatty acids, which consists in treatlng cellulose, perfectly dried by artificial means, with fatty acid anhydrids in press once of a chlorin derivative of sulfuric acid,

substantially as and for the purpose speci- In testimony, that we claim the foregoing as our invention, we have signed our names in presence of two witnesses, this 18th day of November 1910.

BRUNO RICHARD SEIFERT.

FRIEDRICH TODTENHAUPT. Witnesses:

PAUL Alums,

OLKRE SIMON. 

